Energy Conservation Center, Japan / Evaluation Criteria for Machinery and Appliances / Gas Water Heaters

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14. Gas Water Heaters

1) Target Scope:

Water heaters for home use that use gas as fuel. Water heaters for industrial use, bath tub water heaters installed in the bathroom with an oxygen depletion safety shut-off devices, enclosed bath tub gas water heaters connecting ducts to air supply and exhaust opening, and water heaters using gases other than those in the group of city gas 13A and liquefied petroleum gas are excluded.

2) Energy Consumption Efficiency:

For hot water supply sections and bath tub gas water heaters, energy consumption efficiency is heat efficiency (%) measured as specified by JIS S2109.
For heating sections, energy consumption efficiency is heat efficiency (%) value obtained when the value of the temperature difference of circulating warm water becomes the specified level.
For bath tub gas water heaters (with hot water supply functions), energy consumption efficiency is the weighted average value obtained by a 1:3.3 ratio (1 for bath section heat efficiency, 3.3 for hot water supply section heat efficiency).
For gas heaters (with hot water supply functions), energy consumption efficiency is the weighted average value obtained by a 1:3 ratio (1 for heating section heat efficiency, 3 for hot water supply section heat efficiency).

3) Category and Target Values:

Gas instant water heaters, bath tub gas water heaters

Category						Standard energy consumption efficiency
Gas water heater type	Ventilation type	Circulation type		Exhaust type	Category name
Gas instant water heaters	Natural ventilation type			Unvented type	A	83.5
				Non-unvented type	B	78.0
	Forced ventilation type			Non-outdoor type	C	80.0
				Outdoor type	D	82.0
Bath tub gas water heaters (with no hot water supply functions)	Natural ventilation type	Natural circulation type		Vented type or direct vent type (the height where the air supply and exhaust part penetrates external wall is as high as vented types)	E	75.5
				Direct vent type (other than types of the height where the air supply and exhaust part penetrates external wall is as high as vented types)	F	71.0
				Outdoor type	G	76.4
	Forced ventilation type	Natural circulation type			H	70.8
		Forced circulation type			I	77.0
Bath tub gas water heaters (with hot water supply functions)	Natural ventilation type	Natural circulation type	Vented type or direct vent type (the height where the air supply and exhaust part penetrates external wall is as high as vented types)		J	78.0
			Direct vent type (other than types of the height where the air supply and exhaust part penetrates external wall is as high as vented types)		K	77.0
			Outdoor type		L	78.9
	Forced ventilation type	Natural circulation type			M	76.1
		Forced circulation type	Non-outdoor type		N	78.8
			Outdoor type		O	80.4
Gas heaters (with no hot water supply functions)					P	83.4
Gas heaters (with hot water supply functions)					Q	83.0

4) Target Fiscal Year:

Gas instant water heaters and bath tub gas water heaters: 2006
Gas heaters: 2008

5) Energy Conservation Effects:

Gas instant water heaters and bath tub gas water heaters:: Approximately 4.1% improvement in efficiency compared to 2000 levels by 2006.
Gas heaters (with no hot water supply functions): 8.: Approximately 3.3 % improvement in efficiency compared to 2002 levels by 2008.
Gas heaters (with hot water supply functions):: Approximately 1.1% improvement in efficiency compared to 2002 levels by 2008

6) Display Items:

Product name or type, category, energy consumption efficiency, manufacturer's name

7) Place of Display:

Product body and catalogues in which data on performance is shown. For bath tub gas water heaters (with hot water supply functions), in addition to the energy consumption efficiency specified above, the efficiency values of the bath section and hot water supply section measured respectively should be displayed in catalogues that describe performance.
For gas heaters (with hot water supply functions), in addition to the energy consumption efficiency specified above, the efficiency values of the heating section and hot water supply sections measured respectively should be displayed in a catalogues that describe performance.

8) Exemption:

Manufacturers or importers that ship less than 3,000 units in total are excluded, but display obligations must be met regardless of the number of units shipped.

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